Graduate university studies in chemistry; specializations in: Research programme

Study specialization

Research programme

Academic title abbreviation

mag. chem.

Genre

master's thesis

Language

Croatian

Defense date

2016-09-07

Parallel abstract (English)

Within this master thesis, N-(2-carboxyphenyl)glycine − a carboxylic acid with carboxyl groups on aromatic and aliphatic part of the molecule has been synthesized. Its binary solids single crystals with fifteen pyridine derivatives have been prepared by crystalization from so-lution. Obtained compounds were structuraly and thermally characterized by single crystal and powder X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis. In eleven obtained compounds preferentially binding of pyridine nitrogen and aliphatic carboxyl group has observed and it was found that this carboxyl group is a better hydrogen bond donor than aromatic carboxyl group, what is explained by hydrogen bond geometries and calculated NBO charges and electrostatic potentials of carboxyl hydrogen atoms. All noticed hydrogen bond lenghts on aliphatic carboxyl group follows empirical „pKa rule”. Proton transfer from carboxyl group to pyridine nitrogen was observed in eleven compounds leading to formation of salts, while the remaining four are co-crystals. It was also observed that the proton transfer has considerable effect on the crystal packing: in co-crystals molecules are linked into a discrete molecular complexes, while in salts chains of monoanions are observed as the main packing motif.